Doctor Who is...
The Main Character is some random human ( most of the time ) that the doctor picks up, The Doctor is pretty much a mixture of Batman and Mary Poppins, with a time machine
And the show isn't defined by genre; it goes from silly "defeat the alien leader", to horror, to a western, to a murder mystery.. It's a damned good show, and it only gets better as time goes on!
If you want to know the best place to start, start with season 5(2010) and catch up, then you can go back and watch season's 1-4 whenever, they're really good too. But the classic stuff is a whole different beast I wouldn't recommend unless you really really like the show, I enjoy classic Doctor Who but I know it's not for everyone.

To see, just one little thingy, if you will like the show or not... Season 5, episode 1; The Eleventh Hour.

because every ending is mostly the same after them stating in 3 games in a row that choices matter
I knew it there wouldn't be that many endings since the game focusses on good vs evil
nothing changed besides some dialogue

You know, yeah, the ending was awful, I mean, even after the extended cut. It just... it was a severe disappointment.

However, the rest of the game, from the voice acting to the story, including that of the DLC, plus the experimental Multiplayer with in-game story function was outstanding.

I spent over 100 hours on the trilogy, and only disliked five minutes of one game. But it was the ending. I mean, what else could I do? Full Paragon throughout the franchise, completing every side-quest, and the complete loyalty of my team. In the end, Shepard had to die. We all knew it was coming, and we all knew we'd hate how it happened. But that's all it was. FIve minutes. An epic, heartbreaking, and thrilling story of heroism and sheer badassness, right up until the very end.

And what are you gonna do?

At least some of us were left with that last gasp of air. Besides, they could make a similar game based in the same universe. That would be pretty awesome.

There were three choices at the end.
1- Destroy every synthetic life form in the galaxy (Reapers, Geth, and EDI).
2- Take control of the Reapers and become part of their system.
3- Merge all synthetic and organic life forms to create a hybrid and equal existence. This choice isn't given to all players.

After the Extended Cut, you were allowed to simply deny that a choice needed to be made, and the Reapers would Harvest the Earth and whatnot.

If you chose the right ending, you could see Shepard gasp for breath under wreckage.

So, the dialogue isn't all that changed. The overall outcome of the game changed too. And while no specific gaming play style was required to get endings one and two, or the Extended Cut, what else would you expect? The game had to end, and there is only so much that they could have done.

Your decisions in the previous games did make a difference though, and they did matter. They just had no impact on the final ending of the game.